Rubberlike cured polyester-polyamides and process of producing same



P tentedNov. 29, 1949:

- aUnasnuKr-z comm POLYESTER-POLY- 1 mamas AND rnocass'or raonucmo SAME l)a vidW.'Jayne, In, Old Greenwich, Harold M.

Day, Cos Cob. and Edward L. Kropa, Old Greenwich, Conn., assignora to American Cyanamid Company, New

York, N. Y., a corporation of NoDrawing. AppIIeationDecember IS, 194s. SerialNo.717,087

5 Claims. (01. 260-77) 1 This invention relates of linear polyester-polyalnides with glycol esters.

Linear polyesters of high molecular weight are to high molecular weight polyester-polyamides and more specifically, to co-. I condensation products knowni'n the art. These materials are prepared by the reaction of dihydric alcohols with dicarboxylic acids or by the reaction of a hydroxy acid with itself. Moreover. cross-linked polyesters wherein the'linear polyesters are'cross-linkedby means'oi a smalliproportion of a polyfunctional compound are described in the art as, for example, in- Patent No. 2,363,581.

Linear polyamides of high molecular weight such as the well-known nylon may be prepared from aminocarboxylic acids or from polyamines and dicarboxylic acids and are described for example, in'Patents .Nos. 2,071,250, 2,130,523 and others. i a

In our copending applications, Serial Nos.- 717,089 and 717,090 flied Dec. 18,1946, leatherelike cross-linked polyester-polyamides obtained by bringing about reaction between a polyfunctional compound and a linear polyester-polyamide derived from a primary straight-chain monoalkylol amine and a saturated dicarboxylic acid are described and claimed. These leather-like materials can be readily'cold-drawn or calendered, and they .can be molded under heat and pressure.

It is an object of the present invention to prepare derivatives of-linear polyester-polyamides' obtained by reaction of dicarboxylic acids with monoalkylolamines,said derivatives being rubber like materials. v

It is another object of the present invention to bring about reaction between an ester oi an unsaturatedacid and a linear polyester-polyamide to ,eil'ect cross-linking of the latter. 0

Another object of the present invention is th preparation of a high molecular weight crosslinked polyester-polyamide which can be milled, like rubber, with pigments and curing agents and then cured in a rubber mold under heat and pressure to give a vulcanized material with rubberlike properties A still further object of the present invention is to provide a process for roducing resins which can be cured by heating in the presence of an organic peroxide catalyst to produce a rubberlike material.

These and other objects are attained by bringing about reaction between substantially equivalent molar proportions of monoalkylolamine and saturated aliphatic dicarboxylic acid which does not form an anhydride upon heating, and bringing about reaction between the roduct obtained in conjunction with the following specific examples in which-the proportions are given in parts I anda glycol acid ester rated aliphatic dlcarbox'ylic acid, the molar ratio at saturated acid or monoalkylolamine to glycol acid ester beingi'rom about 1:0.15 to about 120.3.

The reaction product is then milled with pigment, i

other filler if desired, and peroxide curing cat alyst, and cured by heating. e

The invention will be described in greater detail byweight. It should be understood that the examples are merely illustrative, and it is not intended that the scope of the invention be limited tothe details therein setiorth.

Example 1 205 parts of sebacic acid (1.0 mol) 89 parts of 2-amino-1-butanol (1.0 mol) 40 parts of ethyleneglycol acid maleate (0.25 mol) The sebacic acid and 2-amino-1-butanol are heated in a vessel fitted with a mechanical agitator at 200 C. for 2 hours while maintaining an atmosphere of carbon dioxide. The ethylene glye col maleate is then added and heating under the carbon dioxide atmosphere continued for. 3 hours.

The resinis milled with a pigment and with 4% by weight of the resin of lauroyl peroxide until both pigment and peroxide are thoroughly'dis- I persed in the resin. The milled stock is then subjected, in a single cavity stainless steel mold, to 500 lbs/in. pressure at'120 C. for 15 minutes. A sheet of rubbery material having a tensile strength of 825 p. s. i. and a 315% elongation at break is obtained.

Example 2 205 arts of sebacic acid (1.0 mol) 31.1 parts of 2-amino-l-butanol (0.35 mol) 39.7 parts of monoethanolamine (0.65 mol) an iron oxide pigment, and with 4% by weight oi 64 parts of ethylene glycol acid maleate (0.4 mol) The sebacic acid, 2-amino-l-butanol and monoethanolamine are maintained at 200 C. under a carbon dioxide atmosphere for hour. The maleate is added and heating continued for one hour. I

The resin is milled with Mapico Red No. 297,

' the resin of lauroyl peroxide, and the milled stock is subjected to a temperature of 90 C. and a pressure of 500 lbs/in. for 15 minutes in a flash mold.

A rubbery product is obtained.

Example 3 210 parts of sebacic acid (1.04 mols) .75 parts of N -methyl monoethanolamine (1.0 mol) 40 parts of ethylene glycol acid maleate (0.25 mol) of an alphabets-unsatuoxide and with 3% by weight of the resin of lauroyl peroxide and molded as in Examples 1 and 2. The cured sheet is rubbery and extremely lively.

Example 4 Example 3 is repeated using an equimolar mixture of N-methyl monoethanolamine and monoethanolamine in place of all-N-methyl monoethanolamine. A good rubbery sheet having a tensile strength of 660 p. s. i., an elongation at break of 300 and a Shore hardness of 68 is ob-- tained.

Example 5 1050 parts of sebacic acid (5.0 molsl The ethylene-glycol acid 222.5 parts of N-ethyl monoethanolamine (2.5

mols) 152.5 parts of monoethanolamine (2.5 molsl 200 parts of ethylene glycol acid maleate (1.25

mols) The sebacic acid, 'N-ethyl monoethanolamine and monoethanolamine are placed in a suitable vessel and heated to 200? C. under an atmosphere of carbon dioxide. The. temperature is maintained at 200 C. for 2 hours, the ethylene glycol Example 6 210 partsof sebacic acid (1.0 mol) 53.4 parts of N-ethyl monoethanolamine (0.6 mol) 24.4 parts of monoethanolamine (0.4 mol).

40 parts of ethylene lycol acid maleate (0.25 mol) The procedure of Example 5 is followed with the following difference: the second heating period is 4 hoursL A rubbery cured product having a tensile strength of 545 p. s. i., a 320% elongation at break and a Shore hardness of 52 is obtained.

. Example 7 205 parts of sebacic acid (1.0 mol) 89 parts of N-ethyi monoethanolamine (1.0 mol) 40 parts of ethylene glycol acid maleate (0.25

mol)

A mixture of the sebacic acid and N-ethyl monoethanolamine is brought to a temperature of 200 C. and, under an atmosphere of carbon dioxide, maintained at that temperature for 2 hours. The acid maleate is then added and heating continued for 3% hours.

The resin obtained is very sticky but it can be milled with pigment and with 3% by weight of resin of lauroyl peroxide as in Example 1. An elastic, rubbery product is obtained.

Example 8 101 parts of sebacic acid (0.5 mol) 37.5 parts of monoisoproparlolamlne (0.5 mol) 32 parts of ethylene glycol acid maleate (0.2 .mol) l The procedure of Example .1 is followed with the following exceptions:

of C. for 15 minutes.

1. The second heating period is 2%, hours. 2. The milled stock is molded at 90 C.

A sheet of rubbery material which has a tensilestrength of 1260 p. s. i. and one of 960 p. s. i. at elongation and 150% elongation at break is obtained.

Example 9.

101 arts of sebacic acid (0.5 mol) 68.5 parts of'N-phenyl monoethanolamine (0.5

mol)

20 parts of ethylene glycol acid maleate mol) The sebacic acid and N-phenyl monoethanolamine are heated in a suitable vessel at 200 C. for 2 hours while maintaining an atmosphere of carbon dioxide over the charge. The acid maleate is then added and heating continued for 23 hours.

50 parts of the cooled resin obtained in'tho manner described above are milled with 75 parts of Mapico Red No. 297, an iron oxide pigment, and with 1.5 parts of lauroyl peroxide and then cured at 500 lbs./in. pressure at a temperature The rubbery material obtained has a tensile strength of 415 p. s. i. and one of p. s. i. at 100% elongation and a 380% elongation at break.

Example 10 100 parts of sebacic acid (0.5 mol) 68.5 parts of N-phenyl monoethanolamine (0.5

mol)

19 parts of ethylene glycol acid maleate (0.125

mol)

The procedure of Example 9 is followed with the following exceptions:'

The first heating period is 17 hours The second heating period is 24 hours The glycol maleate is heated at 200 C. and agitated with carbon dioxide for 10 minutes before use, giving a resin having an acid number of 162.

The rubbery product obtained has a tensile strength of 620 p. s. i. and one of 215 p. s. i. at 100% elongation and a 340% elongation at break.

Example 11 The sebacic acid and N-phenyl monoethanolamine are charged in a vessel fitted with a mechanical agitator and connected to a vacuum pump. The batch is heated to 200 C. at atmospheric pressure with the evolution of steam, at which point the vessel is closed and its contents heated for one hour under vacuum .at 200C.

The vacuumis broken and the condensation product added, after which the mixture is heated at 200 0., again under vacuum, for 34 hours.

The batch is then poured and allowed to cool. It is milled without cooling water on the rolls of the mill with Mapico Red No. 297, an iron oxide pigment, and with 3% of lauroyl peroxide and cured at 90 C. and 500 lbs./in. pressure for- 15 minutes.

The cured sheet, which is rubbery and very lively and resilient, has a tensile strength 01' 700 p. s. i. and a 240% elongation at break.

x; Example 12 70.5 parts of sebacic acid (0.35 mol) 47.5 parts of N-phenyl monoethanolamine (0.35

mol)

8.32 parts of ethylene glycol acid maleate (0.053 mol) The sebacic acid and N-phenyl monoethanolamine are charged in a stainless steel, closed- Jscket resin kettle equipped with a propellertype agitator and a distilling column connected to a vacuum pump. The kettle and its contents are heated by circulating liquid Dowtherm with agitation under atmospheric pressure to 200 C., evolved steam being condensed. Heating is continued for 2% hours under vacuum after which the acid maleate is added and another hours of heating under vacuum is provided.

Milling and curing the cooled product according to the procedure of Example .11 results in a rubbery material which has a tensile strength of 520 p. s. i. and an elongation at break of 350%.

Example 13 64 parts ofsebacic acid (0.32 mol) 43.5 parts of N-phenyl monoethanolamine (0.32

mol)

16.5 parts of the condensation product of diethylene glycol, fumaric acid and sebacic acid in a molar ratio of 6:5:1, having an acid number of about 50 (0.08 mol) 0.11 part of hydroquinone The procedure of Example 12 is followed with the following exceptions:

1. The first heating period is 3 hours 2. The second heating period is 18 hours 3. The hydroquinone is added after 18 hours of the second heating period 4. 6% lauroyl peroxide is added as curing catalyst 5. Curing is effected by heating at 90 C. and

1000 lbs./in. pressure for 10 minutes.

A lively, rubbery material is obtained. It has a modulus of 120 p. s. i. at 100% elongation, a tensile strength of 335 p. s. i., a 360% elongation at break, and a brittle point of 17 C. (0 F.)

Example 14 202 parts of sebacic acid (1.0 mol) 35.6 parts of 2-amino-1-butanol (0.4 mol) 36.6 parts of monoethanolamine (0.6 mol) 29 parts of ethylene glycol acid maleate (0.18

mol)

The sebacic acid, 2-amino-l-butanol and monoethanolamine are heated in a suitable vessel with agitation by means of carbon dioxide to 200 0., and the temperature is maintained for 18 hours. The acid maleate is then added and heating continued for 2 hours.

50 parts of the resin obtained are milled with 75 parts of Mapico Red No. 297, an iron oxide pigment, and then with 2 parts of lauroyl perox-. ide. The milled stock is molded at 120 C. and 500 lbs/in. for 15 minutes.

The cured sheet obtained is leathery in appearance and has a tensile strength of 421 p. s. i., a 210% elongation at break and a Shore hardness of 75.

' Example 15 210 parts of sebacic acid 1.0 mol) 31.1 parts of 2-amino-1-butanol (0.35 mol) 39.7 parts of monoethanolamine (0.65 mol) 40 parts of ethylene glycol acid maleate (0.25 mol) I 8 I The procedure of Example 14 is followed with.

the following exceptions:

1. The first heating period is 35 hour 2. The second heating period is 5 hours 3. The milled stock is molded at C.

A product which isleathery in appearance which has a tensile strength of 770 p. s. i., a

, 290% elongation at break and a Shore hardness of 75 is obtained.

Example 16 The procedure of Example 14 is followed with the following exceptions:

1. The first heating period is hour 2. The second heating period is 2% hours 3. The milled stock is molded at 90 C.

A product which is leathery in appearance and which has a tensile strength of 515 p. s. i., a 310% elongation at break and a Shore hardness of 62 is obtained. I

Example 17 205 parts of sebacic acid (1.0 mol) 26.7 parts of 2-amino-1-butanol (0.3 mol) 42.7 parts of monoethanolamine (0.7 mol) 40 parts of ethylene glycol acid maleate (0.25 mol) v The procedure of Example 14 is followed with the following changes;

1. The first heating period is 66 hours 2. The second heating period is 1 hour 3. 2% of lauroyl peroxide is added as the curing agent A product which is leathery in appearance and which has a tensile strength of 646 p. s. i. and a 200% elongation at break is obtained.

Example 18 The procedure of Example 14 is followed with the following exception:

1. The second heating period is 1 hours A leathery-appearing material having a tensile strength of 955 p. s. i., a 200% elongation at break and a Shore hardness of 92 is obtained.

Example 19 205 parts of sebacic acid (1.0 mol) 31.1 parts of 2-amino-l-butano1 (0.35 mol) 39.7 parts of monoethanolamine (0.65 mol) 40 parts of ethylene glycol acid maleate (0.25

mol)

The procedure of Example 14 is followed with the following exceptions:

A sheet which has the appearance of leather and which has a tensile strength of 935 p. s. i., a

pearance of leather is obtained.

Milling of 50 parts r the resin with 38 parts of calcium carbonate filler, 6 parts oi Mapico Red No. 297, an iron oxide pigment, and 2 parts 01 lauroyl peroxide prior to molding produces an orange-red sheet which has the appearance of leather.

Similarly, 50 p ea of resin are milled with as parts of an olive drab. coloring material and with 2 parts of lauroyl peroxide and then molded to give an olive drab sheet having the appearance Example 20 205 parts of sebacic acidv (1.0 mol) g 31.1 parts of 2-amino-1-but'anol (0.35 mol) 5 39.? parts of monoethanolamine (0.65mol) 43 parts of propylene glycol acid maleate (0.25

mol)

cen

1. The first heating period is 2 hours 2. The second heating period is 2 hours 3. A third heating period of /2 hour in a vacuum oven at 160 C., after transferring the resin to a shallow tray, is provided The molding is carried out at 90 C.

A sheet resembling leather in appearance and having a tensile strength of 835 p. s. i. and a 250% elongation at. break is obtained.

Example 21 205 parts of sebacic acid (1.0 mol) I 31.1 parts of z-amino-l-butanol (0.35 mol) 39.? parts of monoethanolamine, (0.65 mol) 51 parts of diethylene mol) The procedure of Example 14 with the modi flcations enumerated in Example 19 is followed and a sheet resembling leather in appearance and having a tensile strength of 630 p. s. i. and a 245% elongation at break is obtained.

Example 22 205 parts of sebacic acid (1.0 mol) 31.1 parts of N-ethyl monoethanoiamine (0.35

mol) V 39.7 parts of monoethanolamine (0.65 mol) 40 parts of ethylene glycol acid maleate (0.25 mol) The procedure of Example 14 is followed wit the following modifications:

1. The first heating period is 2 hours 2. The second heating period is 3 hours 3. 1.5 parts of lauroyl peroxide are added as the curing catalyst A sheet resembling leather and having a tensile strength of 650 p. s. i. and a 190% elongation at break is obtained.

' Example 23 210 parts of sebacic acid (1.0 mol) 35.6 parts of N-ethyi monoethanolamine (0.4 mol) v 36.6 parts of monoethanolamine (0.6 mol) 7 40 parts of ethylene glycol acid maieate (0.25 mol) The procedure of Example 14 is followed ex- The procedure of Example 14 is followed with the following exceptions:

1. The first heating'period is 2 hours 2. The second heating period is 2% hours 3. 1.5 parts of lauroyi peroxide are used as the curing catalyst 3320 parts of sebacic acid (4.0 mols) 300 parts of monoisopropanolamine (4.0 mole) 80 parts of ethylene glycol acid maieate (1.0 mol) The sebacic acid and monoisopropanolamine are placed in a stainless steel kettle fitted with a mechanical agitator, and the kettle is heated at 200 C. in an oil bath while the charge is kept under an atmosphere of carbon dioxide; Heating is continued for 2 hours, the acid maleate is added, and heating is continued for 4% hours.

After the resin has cooled it is milled with 150% by weightof Mapico Red No. 297, an iron oxide pigment, until the pigment is thoroughly dispersed in the resin. 4% by weight of the resin of lauroyl' peroxide is then added and milled with the pigmented resin until completely dispersed.

The'milled stock is molded in a single cavity flash mold for 15 minutes at 90 C. at 500 lbs/in. pressure to a still sheet having a tensile strength .of 835 p. s. i. and one of 230 p. s. i. at 100% elongation and a 320% elongation at break.

Example 25 a of clay, 1 part of carbon black and 2 parts of glycol acid maleate (0.25

tained.

lauroyl peroxide. Upon molding as in Example 24, a leathery-appearing material having a tensile strength of 615 lbs./in.'- and a 290% elongation at break is obtained.

Eirample 26 50 parts of the resin of Example 24 after the second heating period are milled with 30 parts of clay, 1 part of carbon black, 0.5 part of stearic acid and 2 parts of lauroyl peroxide. After ouring, a material having a tensile strength of 700 lbs./in. and a 310% elongation at break is ob- Ezample 27 The procedure of Example 24 is followed with a 4-hour second heating period instead of 4% hours. The stiiif material obtained after milling and curing has a tensile strength of 960 p. s. i. and one of 270p. s. i. at elongation, and a 340% elongation at break. I

Example 28 94 parts of azelaic acid (0.5 mol) 37.5 parts of monoisopropanoiamine (0.5 mol) 20 parts of ethylene glycol acid maleate (0.125

mol) A The procedure of Example 24 is followed with heating periods of 17 hours and 4 hours, respectively. Milling and curing in the usual manner produces a stiff material having the appearance of'rubber.

. Example 29 205 parts of sebacic acid .(1.0 mol) I 56.2 parts of monoisopropanolamlne (0.75 mol) 14.0 parts of monoethanolamine (0.25 mol). 40 parts of ethylene glycol acid maleate (0.25

mol)

The procedure of Example 24 is followed, adding the monoethanolamine with the monoisopropanolamine and heatingfor 2 hours and 2 hours, respectively. The still material obtained has a tensile strength of 1115 p, s. i. and a 230% elongation at break.

Typical physicalproperties of the cured materials of the present invention which have been reinforced with Mapico Red No. 297, an iron oxide pigment, varying the properties somewhat with the particular resin formulation, are:

Because 01' hydrogen bonding, primary alkylolamines having no side-chain or a side-chain containing only one carbon atom, such as monoethanolamine 0r monoisopropanolamine, give cured products which are less rubbery. We therefore prefer to use alkylolamines such as N-phenyl 'monoethanolamine or 2-amino-1-butanol in the first step or the process 01' the present invention, but it should be understood that the invention is not limited to this preferred embodiment. Moreover, up to about haliof the N-phenyl mono.

ethanolamine or 2-amlno-1-butano1 may be replaced bymonoethanolamine without too much change in the modulus oi the final cured product and, in fact, with an increase in the resistance of the product to swelling in aromatic hydrocarbons.

.conic acid, etc.

Tensile strengtln-. r. .400-1000 p. s. i. Modulus at 100% elongation.200-500 p. s. i. Elongation at break 200-400%' Shore hardness 40-90 Tear resistance 200 lbs./in. thickness Brittle polnt --8 to 17 C. Dielectric strength at 25 c. 300 volts per mil Dielectric constant 24 at 500 volts and 60- cycles 5.5 at 1000 k. c.

0.27 at. 500 volts and 60 cycles 0.06 at 1000'k. c.

Power factor Arc resistance rubber and the butadiene oopol ymers Resist dry heat up to 150 0.

Not affected by exposure to air or sunlight.

Saturated aliphatic dicarboxylic acids which may be used in the present invention arethose which do not form an anhydride upon heating. Acids having at least four carbon atoms between the two carboxyl groups are preferred. Examples of suitable acids are adipic acid, azelaic acid, sebacic acid, plmelic acid, brassylic acid, suberic acid, etc.

Superior to natural Monoalkylola-mines which aresuitable for condensation with a saturated aliphatic dicarboxylic acid to form a linear polyester-polyamide'suscep. tible of cross-linking include monoethanolamine, propanolamine, isopropanolamine, the monobutanolamines, 2-amino-3-hexanol, 3-amino-4- heptanol, 2-amino-4-pentanol, 5-a-mino-4-octanol, 3-amino-3-methyl-2-butanol,' 2-amino-2- methyl-3-hexanoL 2-amlno-2-methyl-l-butanol, 3-amino-3-methyl-2-butanol, 3-amino-3-methyl- 4-heptano1, 3-amino-2-methyl-4-heptanol, etc.

Becondary amines such as N-alkyl, N-aryl and N- aralkyl monoalkylolamines may also be used. Examples are N-phenyl monoethanolamine, N-benzyl monoethanolamine, N-phenylethyl monoethanolamine, N-butyl monoethanolamine, N-methyl monoethanolamine, etc. Mixtures of two or more diflerent monoalkylolamines may also be used, as evidenced by the foregoing examples.

Moreover, a small proportion of a polyfunctional (at least trii'unctional) alkylolamine for example dlethanolamine, polyamine for example diethylenetriamine, or polyhydric alcohol for example glycerol, may be incorporated with the reaction mixture.

Secondary amines or primary amines having a side-chain containing more than one carbon atom generally give the most rubbery products.

Esters or alpha,beta-unsaturated aliphatic dicarboxylic acids suitable for cross-linking of the linear polymers include glycol acid esters oi maleic acid, itaconic acid, fumaric acid, citra- These acids may be esterifled with a glycol such as ethylene glycol, propylene g ycol, butylene glycol, diethylene glycol, triethylene glycol, dipropylene glycol, etc., to produce the corresponding glycol acid esters. Ethylene glycol acid fumarate, diethylene glycol acid maleate,propylene glycol acid itaconate, propylene ably prepared in a two-stage process, both stages oi. which may be-carried out at temperatures between about C. and 220 C. and preferably at about 200 C.

While we do not wish to be limited to any particular theory of mechanism of reaction, we believe that in the first reaction stage substantially equimolar proportions of monoalkylolamine and non-anhydride-forming dicarboxylic acid combine upon heating to form the corresponding amide. The amide, upon further heating, undergoes partial esteriflcation and a linear polymer is built up:

' In the second stage of the process, a mixture of the linear polymer and a suitable glycol acid ester is heated until a resin 01' a definite viscosity (near the gel point) is obtained. This results in the formation of linear polymers of the polyamide-polyester and the glycol ester, said polymers containing the group- .CO,CH=CHCO at intervals in the chain. These linear chains are cross-linked by heating witha small amount of an organic peroxide.

The reactions of the-present process are advantageously carried out under reduced pressure. If desired, the reactants may be heated under course, depend on which alternative is selected.

along with other factors such as the particular reactants involved, the size of the reaction batch.

the amount of heat transfer, etc. In general we prefer to eiil'ect formation of the monomeric amide at atmospheric pressureand then conduct the remainder of the resin formation reaction under reduced pressures of from about i-lO mm. mercury, but the invention is not limited to this preferred embodiment thereof. Moreover, to prevent oxidation, the reaction is preferably carried out in an inert atmosphere as, for'exampie, one of nitrogen, carbon dioxide, etc.

The resin obtained upon reaction of saturated aliphatic dicarboxylic acid, monoalkylolamine and glycol acid ester according to the process of the present invention can be cured by heating with a small amount of an organic peroxide. If the resin is milled on a rubber mill with an appropriate reinforcing pigment and peroxide curing agent, the milled stock can be cured under heat and pressure in a rubber mold to yield a strong and elastic rubber-like product. Since the resins cure rapidly at relatively low temperatures and therefore have a tendency to cure prema turely during milling or to scorch on the mill, it is desirable to utilize cooling water in the milling rolls.

The milled stock may be cured in a rubber mold at 90-120 C. and in -15 minutes at 500-1000 pounds pressure. a Examples of suitable curing catalysts include the acidic peroxides, for example, benzoyl peroxide, phthalic peroxide, succinic peroxide, benzoyl acetic peroxide; the fatty oil acid peroxides, for example, coconut oil acid peroxide, lauric peroxide, stearic peroxide; th alkyl peroxides, for example, tertiary butyl hydroperoxide;'and the terpene peroxides, for example, ascaridole, etc. In general, the concentration of catalyst should be from about 1% to about by weight of the resin..

It may be desirable to add a polymerization inhibitor to the resins of the present invention during their preparation to stabilize them and minimize the amount of scorching on the mill. Suitable inhibitors are/for example, hydroquinone, benzaldehyde, resorcinol, tannin, formaldehyde, sym. alpha,beta-naphthyl-p-phenylene diamine, ascorbic acid, isoascorbic acid,.etc., in an amount equivalent to about 0.1%-1% by weight of the total weight of reaction mixture.

portions of the reactants be carefully controlled,-

and we have found that rubber-like products can be obtained by reacting the saturated aliphatic dicarboxylic acid, the monoalkyloamine, and the glycol acid ester in a molar ratio of from about l:1:0.l5 to'1:l:0.3. V, The materials of the present invention closely resemble rubber, lacking its resilience and highv tensile strength and elongation. However, they are superior to natural rubber in their gasoline, grease and oil resistance, their resistance to deterioration by actinic light, heat and/or air, and

their relatively short time of cure. These and other properties put our new rubber-like products in the class of a specialty product. As such, they have many uses as substitutes for rubber in more or less static applications. Some of these include the fabrication of :Iar rings, shoe soles and heels, gaskets, special tubing, printing and typewriter rolls, etc. In addition, th'eydlnd application in many industrial fieldsincluding laminating, coating, impregnating, etc. For example, the products ofthe present invention, before curing, may

be used as textile or fabric impregnants to produce, after curing of the impregnated material, water-repellent products.

The resins of-the: present invention may be mixed with rubber. whereupon they act not only as anti-oxidants, plasticizers and a means of lowering both the viscosityand the power required during milling, but also as vulcanization accelerators.- They maybe mixed with ester gum and and various alky'd resins, particularly the oilmodlfled air-drying. resins to produce lacquers, varnishes enamels etc. They may also be incorporated with =phenol-formaldehydo resins, urea-formaldehyde resins, thiourea-formaldehyd resins, melamine-formaldehyde resins and other amino-aldehyde resins, either in solution or by admixture as solid resins.

Obviously, suitable fillers, dyes, and pigments may be mixed with the resins to modify the properties thereof as may be desirable. We have found that pigmenting of the resinous products of the present invention increases their tensile strength and any pigment may be incorporated with the resins to produce this effect. Som suitable pigments include iron oxides, carbon black, titanium dioxide, silicon dioxide, etc., as well as other pigments which of suitable size to act as reinforcing pigments. Due to absorption of peroxide by carbon black, it is usually preferably used in admixture with other pigments. Fillers othenthan pigments may also be incorporated with the resinous products of the present invention. These include wood flour, asbestos. calcium silicate, calcium carbonate, magnesium carbonate, talc, paper pulp, clay, glass filaments, mica, cotton flock, silica, etc.

When used in the present specification and claims, the term rubber-like is intended to cover products which may vary rather widely in appearance from rubber to leathery but which have in common the following properties: the products are essentially thermoset and crosslinked chemically, their tensile strengths are increased by pigmenting, they cannot be readily reprocessed such as by calendering or remolding after they have become thermoset, and they can be cured by heating in the presence of an organic peroxide catalyst.

We claim:

1. A rubber-like product obtained by heating at about -220 C. a monoalkylolamine of the formula HO-Y-NHRin which Y is a divalent saturated hydrocarbon radical and R is selected from the group consisting of hydrogen and saturated hydrocarbon radicals with a saturated aliphatic hydrocarbon dicarboxylic acid which does not form an anhydride upon heating, reacting the product'so obtained with a glycol acid ester of an alpha,beta-unsaturated aliphatic hydrocarbon dicarboxylic acid, the molar proportions of saturated acidto alkylolamine to glycol acid ester being from 1:1:0.l5 to 1:1:0.3,-.and then curing the reaction product by heating in the presence of an organic peroxide catalyst.

2. A rubber-like product obtained b heating at about 180-220 C. a monoalkylolamine of the formula HO-Y-NHR in which Y is a divalent saturated hydrocarbon radical and R is selected from the group consisting of hydrogen and saturated hydrocarbon radicals with a saturated aliphatic hydrocarbon dicarboxylic acid which does not form an anhydride upon heating, reacting the product so-obtained with a glycol acid ester of an alpha,beta-unsaturated aliphatic hydrocarbon dicarboxylic acid, the molar proportions of saturated acid to alkylolamine to glycol acid ester being from 1:1:0.15 to 1:1:0.3, milling the resin obtained with a pigment and an organic peroxide curing agent, and curing the milled resin by heatin 3. A product as in claim 2 in which the monoalkylolamine is N-phenyl monoethanolamine.

4. A product as in claim 2 in which the monoalkylolamine is 2-amino-1-butano1.

5. A product as in claim 2 in which the glycol acid ester is the condensation product of diethylene glycol, fumaric acid and sebacic acid in a molar ratio of 6:5:1 having an acid number of about 50.

6. A process of preparing a rubber-like material which comprises heating at about 180-220 C. substantially equivalent molar proportions of a monoalkylolamine of the formula H0--Y--NHR i in which Y is a divalent saturated hydrocarbon radical and R is selected from the group consisting of hydrogen and saturated hydrocarbon radicals and a saturated aliphatic hydrocarbon dicarboxylic acid which does not form an anhydride upon heating for a time at atmospheric pressure and for a time under reduced pressure, heating the product so obtained with a glycol acid ester of an alpha,beta-unsaturated aliphatic hydrocarbon dicarboxylic acid under reduced pressure, the molar ratio of saturated acid to monoalkylolamine to glycol acid ester being from 1:1:0.15 to 1:1:0.3, milling the resin obtained with a pigment and an organic peroxide curing agent, and curing the milled resin by heating.

DAVID W. JAYNE, JR.

HAROLD M.- DAY.

EDWARD L. KROPA.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,333,639 Christ et a1 Nov. 9, 1943 2,363,581 Frosch Nov. 28, 1944 2,406,298 King Aug. 20, 1946 

